US2293255A - Insect repellent - Google Patents

Description

"positio'ns'of unusual efficacy can be made ,by emtibnal. Carbon Company,,lnc., a corporation of 1;,

New York No Drawings Original application June 4, 1938," y

Serial No.,211 ,820. 'Divided and this application August 23, 1940, .Serial No. 353,957; In

Canada March 4 1937 .8Clairns.f(Cl.167 -22) Preparations capable offrepelling. mosquitoes, flies gnats, fieasa;ndother insect pests are genuinely valuable in the {promotion of health and comfort." Thisinventiori is concerned with insect repellents, and itsprimary oject is ,to provide compositionsof improved effectiveness, in insect pests, 1 particularly by test that insect repellent can.-

ploying as their essential ingredients, certain monoor di-alkyl,faryl craralkyl ethers of ethylene and diethylene glycols, or similarmonoethers of the monoacetates of these glycols. It is preferred to selecta substance of thisclass which is relatively non-volatile, or which hasa' boiling point above ab"out.175 (3., and those substances whichhave'butslight odor, orwhich.

unpleasantodorsere mostdesirable. Ingeneral, this class of compounds maybe R2 ,maytbelhydrogen, an alkyl, aryl, aralkyl' or acetyl group, and n is oneor two." specific compounds of this :class whichyare useful in making?- the improvedinsect repellents arezfdiethylene glycol Inonobutyl ether, diethylene glycol nionocompour ds asizepellents include the provision of effective repellency against such insects as ,mosquitoes, house files, stable flies, black"flies and fleas with aminimum of discomfort to the user. .Thesubstances named are all relatively nonfvolatile liquids,and are therefore lastingre- @pellents. Unlike many other repellents, notably essentialyolls such as citronella, these materials are almost odorless, and, if desired, suitable per- .fumes may be incorporated. Preparationscontaining thesematerials may be placed directly in contact withuthe skin orclothing since they have,

possess not in general, substantially no irritating effect upon the skin or"deleterious"action on fabrics. On

sensitive skin,some of these compounds may cause a momentary; smarting sensation, particularly if appliedfull strength." Also, artificial fiber may be softened, andsome textiledyes dissolved, by excessive quantities of certain of these compounds, due to their solvent nature, unless they are diluted or incorporated with. inert materials. Similarly,

these compounds may have acleansing effect on ethyl ether, ethylene glycol monobenzyl ether,

glycol inonobenzyl ether, diethyleneglycol monophenyl ether, ethylene glycol monoeugenyl ether l-allyl 3-methoxy, 4 hydroicy-ethoxy benzene),

diethylene glycol diethyl ether,ethylene glycoldiethylene glycol monophenyl ethen, diethylene the skin,and :they may tend to soften or dissolve paints and cosmeticswith which the repellent comes in contact. ,These compounds are not greasy or oily innature and they may be easily washedoff..:w

; As ,a\ru1e; itis desirable toincorporate small amounts of", certain inert materials, such as vegetable or mineral oils, particularly corn oil,

. with the repellent because on a dry type of skin benzyl etherydiethylene glycol butyl benz'iylether,

and the acetates of any of the monoethers nam d abovew, I v

; wInsecturepellent "compositions containing this class i of: substances generally, and diethylene glycol monobutyl acetate, ethylene glycofmonof phenyl ether-acetate andethylene glycol monobenzyl ether specifically, are the subject of my copending application Serial No. 211,820, filed June 4, ,1938 nowPatent 2,213,156, dated August 2'7, 1940. r

This application is specifically directed to insect repellent compositions containingethylene glycol monophenyl ether; ethylene glycol monoeugenyl ether, diethylene glycol monobenzyl ether and diethylene glycol monophenyl ether are the subject .of my copending application Serial No. 353,958,

filed August 23, 1940.

these repellents sometimes tend to form adry white layer two orthree, hours after application... While thisis in no way harmful, itisundesirable frorn the viewpointof appearance. d

esides tests ,on mosquitoes, various tests have beenmade with these, repellents againstpther insects. For example, in .tests made .in the 1 Adirondacks, black flies (Simulidee 'spp.) were re Inonoethyl ether, 7% corn oil and 28% ethanol pelledfrom skin areas treated with a mixture containing by volume diethylene glycol .monobutyl ether acetate, 15% diethylene glycol 1 for periods ranging from one to two hours.

repellent compositions containing ethylene glycol dibenzyl ether, diethylene glycol butyl benzyl ether, and diethylene glycol monobutyl ether; and

These flies tend to crawl beneath clothing and then inflict their painful bites. This can be prevented toa large extent by placingthe repellent around openings, such as those of the sleeves and collar. l

The abovemixture applied to arms and legs has prevented fleas from alighting and biting these a parts when the user remained in a space heavily -.infested;with theseinsects. Previous to treat- The advantages realized by employing the above ment at least ten to fifteen fleas could be seen crawling about on the legs at any one time. During the test, fleas were continually present, several being visible on the untreated leg whenever it was examined. Protection against the fleas lasted for several hours. t

Other biting flies, such as stable flies (Stomoscys calcitrans) and strawberry or deer flies (Chm/sop spp.) have been'repelled, but against such flies the period of repellency is generally shorter than against mosquitoes. Protection of from one-half to one hour has been obtained against these species. i

The above mixture has also been tried for the protection of animals against insect pests. n dogs it has been effective in repelling fleas for 24 to 48 hours. On cattle, this mixture, containing an additional 5% of diethylene glycol monobutyl ether acetate, incorporated in petroleum oil, has been found to repel house flies (Musca domestica) and small-biting flies (Muscina) for a period of about 4 hours.

The compounds described are, on an average, from two to live times-as eflective repellents as oil of citronella, or from ten to fliteen times as effective as pine oil and the like. Some of the more preferred compounds, such as diethylene glycol butyl benzyl ether, ethylene glycol monobenzyl ether, ethylene glycoldibenzyl ether and diethylene glycol monobutyl ether acetate, have efiective repellencies ranging from live than twelve times that or citronella.

These compounds need not be applied full strength to the body, but may be diluted with inert materials or mixed with one another, or both. In general, dilution with inert materials reduces the efiective repellency of the compound, but in some cases moderate dilution actually renders the compound far more repellent than in the pure state. For example, the repellency of a mixture of equal parts of ethylene glycol monobenzyl ether and ethanol has only about one-third the repellency oi the pure monobenzyl ether, but a mixture oi equal parts of ethanol and diethylene glycol monophenyl ether has a repellency of several times that of the pure monophenyl ether. Further dilution, however, causes a very marked decrease in repellency.

Although the better repellents are relatively nonvolatile (boiling points usually being above about 175 C.) some degree of volatility is necessary to keep the insects-particularly mosquitoes-away from treated parts. Furthermore, odors perceptible to man do not, in themselves, seem to influence mosquitoes to any marked extent. For instance, the odor of citronella will persist long after its repellency has disappeared. Intensity of odor does not seem to aflect the insects either, for certain ofthe butyl compounds have very strong odors yet are not good repellents.

to more The compounds described may be applied, as such, to surfaces from which it is desired to repel the insect pests. They may also be applied as ingredients of lotions compounded with volatile diluents, such as ethanol, or less volatile materials, such as glycerol. The repellents may be applied in combination with various oily carriers, including vegetable oils, such as castor oil and peanut oil, and certain mineral oils. Unguents or creams containing the repellents, as well as powders or carriers of like nature may be eflectively used. In any of the diflerent modes of application, it will be understood that mixtures or blends of the individual repellents may be employed.

My invention is not limited to the specific substances named, and it includes modifications within its scope as deflned by the appended claims.

This application is a division of my copending application Serial No. 211,820, flled June 4, 1938, which, in turn, contains subject matter in common with my application Serial No. 68,191, flled March 11, 1936, with which it was copending.

I claim:

1. An insect repellent composition which contains a substantial proportion of an essential repellent ingredient of the group consisting oi ethylene glycol dibenzyl ether, diethylene glycol butyl benzyl ether and diethylene glycol monobutyl ether.

2. An insect repellent composition which contains ethylene glycoldibenzyl ether as an essential repellent ingredient.

3. An insect repellent composition which contains diethylene glycol butyl benzyl ether as an essential repellent ingredient.

4. An insect repellent composition which contains diethylene glycol monobutyl ether as an essential repellent ingredient.

5. An insect repellent composition which is composed of an inert diluent and an essential repellent ingredient of the group consisting of ethylene glycol dibenzyl ether, diethylene glycol butyl benzyl ether and diethylene glycol monobutyl ether.

6. An insect repellent composition which is composed of an inert diluent and ethylene glycol dibenzyl ether as an essential repellent ingredient.

7. An insect repellent composition which is composed of an inert diluent and diethylene glycol butyl benzyl ether as an essential repellent ingredient.

8. An insect repellent composition which is composed of an inert diluent and diethylene glycol monobutyl ether as an essential repellent ingredient.

PHILIP GRANE'I'I.